/**
 * @brief 定义链表的结点和对应的构造函数
 *
 */
#pragma once
struct ListNode {
  int data_;
  ListNode* next_;
  ListNode() : data_(0), next_(nullptr){};
  ListNode(int data) : data_(data), next_(nullptr){};
  ListNode(int data, ListNode* next) : data_(data), next_(next){};
};
